Apple’s engineers have been busy beavering away at patent applications again, and 3D head-tracking displays, intelligent iPod playback and more active battery management all seem to be on the Cupertino workbench. Of the three, the most interesting is probably Apple’s work to use video, infrared or electromagnetic field tracking to move an on-screen object or interface according to the angle at which you’re looking at it. Not only would the system work for 3D objects, but 2D UIs could be fanned or scrolled through depending on head position.

Meanwhile a second patent application documents a more intelligent track handling system for iPods or iPhones, which would monitor and remember playback choices the user makes for individual tracks. That way, specific equaliser settings could automatically be switched between depending on previous choices made for the same music:

“For example, the usage metadata may indicate that a user skips, on average, the first 22 seconds of a particular song so the next time that song is played, the first 22 seconds will automatically be skipped.” Apple patent application

Finally, Apple are looking at improved power monitoring for their portable devices, and giving iPods and other units the ability to warn users that there is not enough juice left, say, for video playback. The user would then be offered a choice of waiting or of lowering backlighting, say, to eke out enough charge.